I'm not a lawyer or expert.Just another opinion.
IMO,a blank first round presents a conflict.
When is it appropriate to use deadly force?
When I see the bad guy has the means and intent to cause me great harm,right now.
If those conditions have been met,why would I present a blank? I'm not talking about the gun shop guys train of thought,I'm talking about the prosecutor asking the question.
Forgive me,I've never been in court over more than a traffic ticket. I have learned from TFL to think in terms of the prosecutor if I am going to carry a weapon.
I would not count on help from " In case my first round was unintentional..."
I would expect the prosecutor would view the blank similar to a warning shot.
If you are shooting a warning shot,you are shooting to gain control,not to stop a killer.
The cute ideas are bad ideas because they lead to introducing a firearm without quite seriously accepting what it means.
And how does a first round blank fit the four rules of safety?
1) The gun is loaded,not "sort of loaded"
2) I don't point it till I intend to destroy the target.The blank says "I do not intend to hurt the target,but I will point a gun at it, its OK,because its not really loaded,the first round is a blank???
No.
Its an entirely wrong mindset for carrying a SD weapon.